The 70-kDa epileptic cortical protein elicits bursting activity accompanied by a reduction of outward current in Euhadra neurons which is inhibited by an antibody against this protein.
The effect on membrane properties of 70-kDa protein (namely P70), a specific protein found in cobalt-induced epileptic cortex of rats, was examined electrophysiologically in identified neurons of the snail, Euhadra peliomphala. Injection of P70 into the neurons elicited a bursting activity resembling the paroxysmal depolarization shift seen in mammalian epileptic neurons and a reduction of the outward current, which were suppressed by Ca2(+)-free saline or tetraethylammonium. The injection of P70-antibody into neurons, preceding the P70 injection, markedly inhibited the bursting activity and the reduced outward current elicited by P70. These findings suggest that P70 causes a reduction of Ca2(+)-dependent potassium conductance which may be one of the mechanisms generating epileptic bursting activity.
Onozuka
M
M
Department of Anatomy, Gifu University School of Medicine, Japan.
Imai
S
S
Ozono
S
S
D000818:Animals; D000906:Antibodies; D002540:Cerebral Cortex / Q000503:physiopathology; D003035:Cobalt; D004827:Epilepsy / Q000139:chemically induced / Q000503:physiopathology*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D051381:Rats; D012908:Snails
D000906:Antibodies; D009419:Nerve Tissue Proteins; D003035:Cobalt